A plurality of vehicle keys may be associated with a single vehicle. For example, a main key may include all functions including starting the engine, while a sub key may be limited in functions such as being unable to unlock private compartments such as a trunk or a glove compartment.
Personal property, personal information, etc. may be stored in these private spaces such as the trunk or glove compartment. In other to protect these from theft, precautions are taken such as locking a trunk opening switch inside the glove compartment, or locking the glove compartment with a main key.